CN113645921B

CN113645921B - Personal care device with detachable coupling in drive train

Info

Publication number: CN113645921B
Application number: CN202080021340.6A
Authority: CN
Inventors: P·桑切斯马丁内兹; H·布德克
Original assignee: Braun GmbH
Current assignee: Braun GmbH
Priority date: 2019-05-02
Filing date: 2020-04-29
Publication date: 2023-05-30
Anticipated expiration: 2040-04-29
Also published as: WO2020222136A1; EP3733118A1; EP3733118B1; US11635111B2; US20200347890A1; CN113645921A; JP7376614B2; JP2022531397A

Abstract

The present disclosure relates to a personal care device having: a head portion having a driven processing head; a handle portion having a drive unit for providing a movement having a direction of movement; and a drive train extending between the drive unit and the driven processing head for transmitting motion from the drive unit to the driven processing head, the drive train having a detachable coupling. The separable coupling has: a first coupling part having a first coupling element; a second coupling part having a second coupling element, the first coupling element and the second coupling element being detachably engaged with each other; and a resilient element biasing the first and second coupling elements against each other such that the first and second coupling elements engage in a play-free manner in the direction of movement.

Description

Personal care device with detachable coupling in drive train

Technical Field

The present disclosure relates to a personal care device having a drive train for coupling a drive unit with a driven treatment head, wherein the drive train has a detachable coupling.

Background

It is generally known that personal care devices may include a handle portion and a head portion that is detachable from the handle portion, for example, for cleaning purposes or for replacement. In the case of a head portion comprising a driven treatment head, this requires that the drive train between the drive unit in the handle portion and the driven treatment head in the head portion must be separable. The detachable coupling may then for example comprise two gears with gear teeth, which in the attached state engage each other and become disengaged once the head portion and the handle portion are detached from each other.

It is a general object to improve personal care devices of the type described, in particular, with respect to their noise behaviour and/or wear of the detachable coupling parts.

Disclosure of Invention

According to one aspect, there is provided a personal care device having: a head portion having a driven processing head; a handle portion having a drive unit for providing a movement having a direction of movement; and a drive train extending between the drive unit and the driven processing head for transmitting the motion from the drive unit to the driven processing head, the drive train having a detachable coupling. The separable coupling has: a first coupling member having a first coupling element; a second coupling part having a second coupling element, the first coupling element and the second coupling element being detachably engaged with each other; and a resilient element biasing the first and second coupling elements against each other such that the first and second coupling elements engage in a gapless manner along the direction of motion.

Drawings

The present disclosure and the personal care apparatus of the present invention will be further described by the detailed description with reference to the accompanying drawings. In the drawings of which there are shown,

FIG. 1A is a schematic diagram of an exemplary personal care device according to the present disclosure;

FIG. 1B is an enlarged view of the separable coupling shown in FIG. 1A;

FIG. 2 is a schematic, perspective, single-view illustration of one exemplary coupling component of a separable coupling according to the present disclosure; and

fig. 3 is a schematic, perspective, individual view of another exemplary coupling component of a separable coupling according to the present disclosure.

Detailed Description

In the context of the present specification, "personal care" shall mean the nutrition (or care) of the skin and its appendages (i.e. hair and nails) and teeth and oral cavity (including tongue, gums, etc.), wherein the aim is to prevent diseases and to maintain and enhance health ("care"), on the one hand, and to cosmetically treat and improve the appearance of the skin and its appendages or teeth and oral cavity, on the other hand. It should include maintaining and enhancing well-being. This includes skin care, hair care and oral care, and nail care. This also includes grooming activities such as beard care, shaving and dehairing. Thus, "personal care device" refers to any device for performing such nutritional or grooming activities, for example a (cosmetic) skin treatment device such as a skin massaging device or a skin brush; a wet shaver; an electric razor or trimmer; an electric dehairing device; and oral care devices such as manual or electric toothbrushes, (electric) flossing, (electric) irrigators, (electric) tongue cleaners, or (electric) gum massagers. This should not exclude that the proposed personal care system may have more significant benefits in one or several of these nutritional or device areas than in one or several other of these areas.

According to the present description, the drive train of the personal care device of the present invention comprises a detachable coupling comprising a first coupling part and a second coupling part. The first coupling part comprises a first coupling element and the second coupling part comprises a second coupling element. The first coupling element and the second coupling element engage each other in the attached state to enable a transfer of motion from the first coupling part to the second coupling part or vice versa. The detachable coupling further comprises a resilient element which biases the first coupling element and the second coupling element against each other and by this bias also ensures that the two coupling elements engage each other in a play-free manner, in particular in the direction of movement of the movement which should be transmitted from the drive unit to the driven treatment head. Since there is no gap between the coupling elements, the two coupling elements will not substantially disengage from each other during operation. Such disengagement may otherwise create noise (as the coupling elements will eventually collide with each other) and may also result in wear of the two engaged coupling elements. In the direction of movement, the first coupling element and the second coupling element interact via abutting force transmission surfaces, which are provided at substantially inelastic portions of the first coupling element and the second coupling element. This means that the elastic elements are arranged elsewhere, but not in the direction of movement (see below for an arrangement of two elastic elements). The elastic element may be arranged in the reverse direction of movement. The force transmission surfaces are arranged at the sides of the first coupling element and the second coupling element, which are not elastic in design. This should achieve good power transfer and deflection of the components providing the force transfer surface does not consume energy. Since all materials have a certain elasticity, the elastic properties of the component on which the force-transmitting surface is arranged should be smaller than the elastic properties of the elastic element. Expressed as a spring constant, the spring constant of the component realizing the force transmitting surface is at least about twice higher than the spring constant of the elastic element.

The resilient element may be designed such that the applied biasing force is higher than the usual force occurring in the reverse direction of movement during normal operation of the personal care device. A force higher than the biasing force and acting in the opposite direction of movement will deflect the spring element and will thus result in a disengagement of the first coupling element and the second coupling element. Thus, the biasing force may be defined by measuring typical forces occurring during normal operation of the personal care device and by setting a threshold such that disengagement of the first coupling element and the second coupling element occurs only during 50% or less, or 25% or less, or 10% or less, or 5% or less, or 4%, 3%, 2%, or 1% or less of the treatment cycle on average.

In at least one embodiment, the first coupling part and the second coupling part comprise further coupling elements of the engagement pair, for example at least the second pair of coupling elements. The separable coupling may have three or four or more pairs of mating coupling elements. In such embodiments, a second resilient element may be provided, which may then be arranged in the direction of movement such that the coupling elements of the second pair of coupling elements are biased against each other and interact at the force transmitting surface arranged in the opposite direction of movement. This allows the direction of movement to be reversed without losing the effect of the movement transfer via the force transfer surface being substantially inelastic.

The motion transferred from the drive unit to the driven processing head may be a rotational motion. In some embodiments, the rotational movement may be a swinging rotational movement, or the personal care device may comprise a possibility to reply to the rotational movement, for example by means of a corresponding input device such as a button or a touch screen. Nor should it be excluded that the movement is a linear movement or a more complex movement.

In at least one embodiment, the first coupling element is one of a receiving portion (also referred to as a receiver) and a protrusion (e.g., a pin), and the second coupling element is the other of the receiving portion and the protrusion. The receptacle may have an open end in a direction along which the first coupling part and the second coupling part are intended to be separated. The open end may have a bevel to accommodate easy attachment of the separated coupling parts, wherein the protrusion will be guided into the receiving portion despite the offset between the two coupling elements due to the bevel.

The elastic element may be integrally arranged with one of the first coupling part or the second coupling part, for example, in the above-described example, it may form one side of the receiving portion. The spring element may comprise a spring arm which is deflectable in the coupled state from a rest position into a deflected position. For example, when the coupling parts are attached, the first coupling element is realized as a receiver and the second coupling element is realized as a protrusion engaging with the receiver. One side of the receptacle may then be realized by a resilient element, such as a spring arm, which is deflectable into the hollow. The receptacle can now be designed to be smaller than the corresponding dimension of the projection into the receptacle. The larger size of the projection deflects the spring arm of the resilient element from its rest state to a deflected state. Under such deflection, the resilient element provides a biasing force that urges the two coupling elements against each other. The elastic elements may in particular be arranged in a direction opposite to the direction of movement, such that during operation the two coupling elements transmit movement via the two force transmitting surfaces which have been discussed without elasticity (ignoring any elasticity of the bulk material from which the coupling elements are made). The elastic element may be made of the same material as the coupling part integrally providing the elastic element. The material may be a plastic material such as polyoxymethylene, which should not exclude any other material. In some embodiments, at least a portion of the resilient element is made of metal, such as spring metal forming a leaf spring that may be at least partially overmolded with plastic, for example.

The treatment head and the handle portion of the personal care device may be arranged to be pivotable relative to each other about at least one pivot axis. To accommodate such relative pivotal movement of the first and second coupling parts, the detachable coupling may be realized as a detachable universal joint. The pivot angle may have an absolute range of about 1 to 50 degrees. The handle portion and the treatment head may also be arranged to be pivotable with respect to each other about two, in particular perpendicular, pivot axes.

The handle portion and the head portion may be secured to each other by means of at least one pair of separable mechanical connector elements, such as a clasp and a corresponding receiver for receiving the clasp.

Fig. 1A is a schematic view of an exemplary personal care device 1 according to the present disclosure. The personal care device 1 has a head portion 10 and a handle portion 20 detachably connected to each other. The head portion 10 comprises a treatment head 11, which treatment head 11 has at least a part arranged to be driven in motion (for simplicity, in the following, treatment head 11 is driven during operation of the personal care apparatus, it should be understood that at least a part of treatment head 11 is driven, which should not exclude that the complete treatment head 11 is driven in motion). The drive unit 30 is arranged in the handle section 20. A drive train 40 extends between the drive unit 30 and the processing head 11 to transfer the motion provided by the drive unit 30 to the processing head 11. The drive train 40 comprises a detachable coupling 50, which is arranged such that when the head portion 10 and the handle portion 20 are detached, the detachable coupling 50 also becomes detached. The head portion 10 and the handle portion 20 may include at least one pair of

mechanical connector elements

12, 22. The head portion 10 may include a mechanical connector element 12 and the handle portion 20 may include a mechanical connector element 22, the pair of

mechanical connector elements

12, 22 mechanically connecting the head portion 10 and the handle portion 20 together. In some embodiments, the head portion 10 and the handle portion 20 comprise two or more pairs of mechanical connector elements. One of the

mechanical connector elements

12, 22 may be arranged as a clasp and the other may be arranged as a receiver for receiving at least a portion of the clasp (e.g., the nose of the clasp). This should not exclude caps that may use other mechanical connector elements.

The separable coupling 50 has a first coupling member 510 and a second coupling member 520 that are detachably engaged with each other as will be described in detail with respect to fig. 1B. The separable coupling 50 further includes a resilient member 530.

Fig. 1B is an enlarged view of the separable coupling 50 shown in fig. 1A. The first coupling part 510 includes a first coupling element 511A, and the second coupling part 520 includes a second coupling element 512A. It is also shown that the drive train 40 comprises a first shaft 513 connected with the first coupling part 510 for transmitting the movement M1 provided by the drive unit and a second shaft 523 connected with the second coupling part 520 for transmitting the movement M2, wherein m2=m1 when the coupling 50 does not have any transmission ratio. The coupling 50 can be separated by moving the first coupling part 510 relative to the second coupling part 520 in the separation direction S1, or vice versa by moving the second coupling part 520 relative to the first coupling part 510 in the separation direction S2.

In the embodiment shown, the elastic element 530 is realized as an element integral with the first coupling part 510. This should be understood as a non-limiting example, and the resilient element 530 may also be arranged at the second coupling part 520, or may otherwise form part of the detachable coupling 50. In the example shown, the resilient element 530 includes the spring arm 531 in a deflected position (the hollow 532 is disposed behind the spring arm 531 such that the spring arm 531 has sufficient position to deflect). Accordingly, the spring arm 531 applies a biasing force F to the second coupling element 521A, pushing the force transfer surface 522A of the second coupling element 521A against the force transfer surface 512A of the first coupling element 511A. Due to its designed elastic properties, i.e. its spring properties, the spring arm 531 of the elastic element 530 will move back to its rest position when the first coupling part 510 and the second coupling part 520 are disengaged (i.e. separated). By means of the elastic element 530, the first coupling element 511A and the second coupling element 521A are engaged in a play-free manner with respect to the direction of movement M1. Because of the zero clearance engagement and because of the biasing force F, the first and

second coupling elements

511A, 521A will substantially always be in force transmitting contact at their

force transmitting surfaces

512A, 522A. In the case of gaps between the coupling elements, uneven movement of the drive unit or loads on the treatment head can cause the coupling elements to come into loose contact, in particular repeatedly, and then collide with one another again when they come into contact again, which generates noise and wear of the components. The resilient element 530 may be arranged such that the biasing force is greater than the typical force that may be exerted by the second coupling element 522A at the spring arm 531. In some embodiments, the drive train 40 may include an overload clutch such that the force applied at the resilient element 530 is limited.

In fig. 1B, it is indicated that the separable coupling 50 can have more than one pair of

coupling elements

511A, 521A. Two additional pin-

like coupling elements

521B and 521C are shown, which engage with corresponding receiver-like coupling elements provided at the first coupling part 510. When the relative position between the first coupling part 510 and the second coupling part 520 is defined by the first pair of

coupling elements

511A, 521A, any other pair of coupling elements need not be engaged in a gapless manner. In some embodiments, a second resilient element may be present and may be arranged with the second pair of coupling elements in a manner that mirrors the arrangement of resilient element 530 and first pair of

coupling elements

511A and 521A shown with respect to the direction of motion M1. Such a mirrored arrangement would then take over the transfer of force in the reverse direction of motion M1'. In the case where only the elastic member 530 and the illustrated arrangement of the first pair of

coupling members

511A and 521A are present, when the direction of movement is reversed to M1', some energy will be lost due to the elasticity of the elastic member 530.

Fig. 2 is a schematic perspective view of an exemplary coupling member 300 that may be used as either the first coupling member or the second coupling member of the detachable coupling according to the present disclosure. The coupling member 300 is arranged at the end of the shaft 310 and comprises a base element 320 and three

protrusions

321, 322 and 323, each realized as a pin extending radially outwards from the base element 320, with an angular offset of 180 degrees between each pair of

adjacent protrusions

321 and 322, 322 and 323 and 321. The

protrusions

321, 322, and 323 (i.e., their centerlines) extend in a plane perpendicular to the longitudinal axis along which the shaft 310 extends. In contrast to the example shown, it is substantially sufficient if one coupling part has one projection engaging with the receiving portion of the other coupling part of the detachable coupling. Instead of one projection or three projections as shown, the respective coupling part may have two projections or four projections or the like. The coupling element provided as a projection may take any form and is not limited to a pin. In case two or more coupling elements are realized as protrusions, each of the coupling elements may have its own shape and position.

Fig. 3 is a schematic perspective view of an exemplary coupling member 400 that may be used as either the first coupling member or the second coupling member of the detachable coupling according to the present disclosure. In particular, the coupling member 400 may be engaged with the coupling member 300 shown in fig. 2 to form a separable coupling. The coupling member 400 is arranged at an end of the shaft 410 and includes a base element 420 and three receiving

portions

421, 422 and 423 and an elastic element 430. Each of the receiving

portions

421, 422 and 423 is formed by walls of the base member 420 and the

adjacent wall members

421A, 422A, 423A, and in the case of the receiving portion 421, one of these walls is defined by a wall of the spring arm 431 of the elastic member 430. The

wall elements

421A, 422A and 423A each extend substantially in a direction parallel to the longitudinal extension direction of the shaft element 410. Once the coupling element 400 has received the respective protrusion from the engaging coupling member, the protrusion and receiving

portions

421, 422 and 423 are intended to interact along the

force transmitting surfaces

421F, 422F and 423F of the

wall elements

421A, 422A and 423A, respectively, such that a movement M3 in a counter-clockwise direction is generated. Further, the projection intended to engage with the receiving portion 421 has a dimension slightly larger than the opening width of the receiving portion 421 in the circumferential direction, and bends the spring arm 431 of the resilient element 430 from its shown rest position into a deflected position, wherein the spring arm 431 moves into the hollow 432 and biases the projection against the force transmitting surface 421F. With this arrangement, the protruding portion (e.g., protruding portion 321 as shown in fig. 2) and the receiving portion 421 are engaged in a gapless manner in the circumferential direction (i.e., in the direction of movement M3), and any noise and wear due to repeated disengagement of the protruding portion and the receiving portion during operation are effectively reduced.

Instead of two engaging coupling members (each having only a protrusion and a receiving portion) as shown in fig. 2 and 3, the engaging coupling members may each have a mixture of protrusions and receiving portions, e.g. each coupling member may have one protrusion and one receiving portion.

The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Rather, unless otherwise indicated, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as "40mm" is intended to mean "about 40mm".

Claims

1. A personal care apparatus (1), comprising:

a head portion (10) having a driven processing head (11);

-a handle portion (20) having a drive unit (30) for providing a movement having a direction of movement; and

-a drive train (40) extending between the drive unit (30) and the driven processing head (11) for transmitting the motion from the drive unit (30) to the driven processing head (11), the drive train (40) comprising a detachable coupling (50);

the separable coupling (50) includes:

a first coupling part (510) having a first coupling element (511A);

-a second coupling part (520) having a second coupling element (521A), the first coupling element (511A) and the second coupling element (521A) being detachably engaged with each other; and

-a resilient element (530) biasing the first coupling element (511A) and the second coupling element (521A) against each other such that the first coupling element (511A) and the second coupling element (521A) engage in a gapless manner along the direction of movement;

wherein the driven treatment head (11) and the handle portion (20) are arranged for being pivotable relative to each other about at least a first pivot axis, the detachable coupling (50) being a detachable universal joint.

2. The personal care device according to claim 1, wherein the resilient element (530) is arranged for biasing the force transmitting surface (512A) of the first coupling element (511A) and the force transmitting surface (522A) of the second coupling element (521A) against each other.

3. The personal care apparatus according to claim 1 or 2, wherein the movement is a rotational movement, wherein the drive train (40) comprises a first shaft (513) and a second shaft (523) coupled by the detachable coupling (50), the first shaft (513) being coupled with the drive unit (30) and the rotational movement being a movement about a longitudinal axis (L) of the first shaft (513) and the direction of movement being circumferential with respect to the first shaft (513).

4. The personal care device according to claim 1 or 2, wherein the first coupling element (511A) and the second coupling element (521A) form a first pair of coupling elements, and the separable coupling (50) comprises at least a second pair of coupling elements.

5. The personal care device according to claim 4, wherein the separable coupling (50) comprises a second resilient element arranged to urge the coupling elements of the second pair of coupling elements against each other such that the force transmitting surfaces of the second pair of coupling elements interact with each other when the direction of movement is reversed.

6. The personal care device according to claim 1 or 2, wherein one of the first coupling element (511A) or the second coupling element (521A) is realized as a receiver (421), and the other of the first coupling element (511A) and the second coupling element (521A) is realized as a protrusion (321) detachably engaged with the receiver.

7. The personal care device of claim 6, wherein the receptacle (421) has an open end in a separation direction, and wherein a bevel is formed at the open end of the receptacle (421).

8. The personal care device according to claim 1 or 2, wherein the resilient element (530) is integral with one of the first coupling part (511A) or the second coupling part (521A).

9. The personal care device according to claim 8, wherein the resilient element (530) and the coupling part realized integrally with the resilient element are made of plastic material.

10. The personal care device according to claim 1 or 2, wherein the resilient element (530) comprises a spring arm (531) arranged to deflect when the detachable coupling (50) is in a coupled state.

11. The personal care device according to claim 1 or 2, wherein the resilient element is designed to provide a biasing force (F) which is greater than a force normally applied in a reverse direction of movement during operation of the personal care device.

12. The personal care device of claim 1 or 2, wherein a total pivot angle about the first pivot axis is in a range between 1 degree and 50 degrees.

13. The personal care device according to claim 1 or 2, further comprising at least one pair of separable mechanical connector elements for mechanically connecting the handle portion (20) and the head portion (10).

14. The personal care device according to claim 1 or 2, wherein the resilient element (530) is at least partly made of spring metal.

15. The personal care device of claim 4, wherein the separable coupling (50) comprises at least three pairs of coupling elements.

16. The personal care device of claim 6, wherein the protrusion (321) is a pin.

17. The personal care device of claim 9, wherein the plastic material is a polyoxymethylene material.

18. The personal care device of claim 14, wherein the resilient element (530) is at least partially made of spring sheet metal.